A method of surface coating a metallic object, including removing substantially all of the existing silver sulfide tarnish if present, ultrasonically cleaning the object with immersion in a solvent, uniformly dispersing selected nanoparticles over the surface of the object by sonicating the object in an ultrasonic bath containing the selected nanoparticles. The invention further includes quickly rinsing the object with solvent upon removal from the ultrasonic bath to inhibit formation of large agglomerates, drying the object with a flow of gas, optically inspecting the object for the presence of agglomeration and applying a barrier layer conformal coating and a protective layer conformal coating.